feat(rbac): enforce admin access checks and document permission model

apps/admin/src/lib/access.ts

@@ -0,0 +1,105 @@
+import { hasPermission, normalizeRole, type PermissionScope, type Role } from "@cms/content/rbac"
+import { cookies, headers } from "next/headers"
+import type { NextRequest } from "next/server"
+
+type RoutePermission = {
+  permission: Parameters<typeof hasPermission>[1]
+  scope: PermissionScope
+}
+
+type GuardRule = {
+  route: RegExp
+  requirement: RoutePermission | null
+}
+
+const guardRules: GuardRule[] = [
+  {
+    route: /^\/unauthorized(?:\/|$)/,
+    requirement: null,
+  },
+  {
+    route: /^\/todo(?:\/|$)/,
+    requirement: {
+      permission: "roadmap:read",
+      scope: "global",
+    },
+  },
+  {
+    route: /^\/(?:$|\?)/,
+    requirement: {
+      permission: "dashboard:read",
+      scope: "global",
+    },
+  },
+]
+
+function resolveDefaultRole(): Role | null {
+  if (process.env.NODE_ENV === "production") {
+    return null
+  }
+
+  return normalizeRole(process.env.CMS_DEV_ROLE ?? "admin")
+}
+
+function resolveRoleFromRawValue(raw: string | null | undefined): Role | null {
+  return normalizeRole(raw)
+}
+
+export function resolveRoleFromRequest(request: NextRequest): Role | null {
+  const roleFromCookie = request.cookies.get("cms_role")?.value
+  const roleFromHeader = request.headers.get("x-cms-role")
+
+  const resolved = resolveRoleFromRawValue(roleFromCookie ?? roleFromHeader)
+
+  if (resolved) {
+    return resolved
+  }
+
+  return resolveDefaultRole()
+}
+
+export async function resolveRoleFromServerContext(): Promise<Role | null> {
+  const cookieStore = await cookies()
+  const headerStore = await headers()
+
+  const roleFromCookie = cookieStore.get("cms_role")?.value
+  const roleFromHeader = headerStore.get("x-cms-role")
+
+  const resolved = resolveRoleFromRawValue(roleFromCookie ?? roleFromHeader)
+
+  if (resolved) {
+    return resolved
+  }
+
+  return resolveDefaultRole()
+}
+
+export function getRequiredPermission(pathname: string): RoutePermission {
+  for (const rule of guardRules) {
+    if (rule.route.test(pathname)) {
+      return (
+        rule.requirement ?? {
+          permission: "dashboard:read",
+          scope: "global",
+        }
+      )
+    }
+  }
+
+  return {
+    permission: "dashboard:read",
+    scope: "global",
+  }
+}
+
+export function canAccessRoute(role: Role, pathname: string): boolean {
+  const rule = guardRules.find((item) => item.route.test(pathname))
+
+  if (rule && rule.requirement === null) {
+    return true
+  }
+
+  const requirement = getRequiredPermission(pathname)
+
+  return hasPermission(role, requirement.permission, requirement.scope)
+}